On the dynamic nature of microscopy specimens at lattice resolution

2014 Examples are shown that illustrate rapid changes that can take place while a thin foil specimen is under observation in a high-voltage microscope. These unusually dramatic examples emphasize the fact that for correct characterization of structural details of any crystalline material by lattice imaging microscopy particularly at surfaces, interfaces, and other defects, it is essential never to overlook the possibility that local structural features or atomic-scale defects may have been changed in the microscope prior to the recording of a micrograph or during preparation of the thin foil speciment. Electron beam induced atomic mobility combined with sequential high resolution imaging are shown to provide interesting details concerning the structure of gold and GaAs surfaces of different crystallographic orientations. Tome 50 N°24 15 DÉCEMBRE 1989 J. Phys. France SO (1989) 3431-3440 15 DÉCEMBRE 1989,